BACKGROUND
1 . Technical Field
The present disclosure relates to screws and, more particularly, to a screw having an elastic member to prevent the screw from loosening.
2. Description of Related Art
Screws are used to connect various articles together. Special nuts and lock washers are often used to prevent a screw from loosening. The need for additional elements to prevent loosening adds to the expense and complication of attaching articles together.
BRIEF DESCRIPTION OF THE DRAWINGS
The components in the drawing are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the loosening proof screw.
The drawing is a schematic view of a locking screw in accordance with an exemplary embodiment with a head of the screw cut-away to exposed internal details.
DETAILED DESCRIPTION
Referring to the drawing, a
locking screw 1 can be used to connect two or more articles together. In the embodiment, a
first article 40 and a
second article 50 are illustrated as an example. The
locking screw 1 includes an externally threaded
shaft 10, a
head 20, and an
elastic member 30. The
articles 40 and
50 can be connected together by the engagement of the
screw 1 with internally threaded holes of the
articles 40 and
50.
The
head 20 defines a
chamber 201 in which a
spiral groove 2011 is defined. The
spiral groove 2011 is configured to receive one end of the
elastic member 30. The
shaft 10 extends from the bottom of the
chamber 201.
In use, the
elastic member 30 is arranged around the
shaft 10. One end of the
elastic member 30 is received in the
spiral groove 2011 of the
chamber 201, and the other opposite end of the
elastic member 30 abuts against the
top surface 401 of the
first article 40 when the
shaft 10 is screwed into the threaded holes of the
first article 40 and the
second article 50. The
elastic member 30 is rotatable in the
spiral groove 2011 to change an effective length of the
elastic member 30 along a longitudinal axis of the
shaft 10. In this embodiment, the effective length of the
elastic member 30 along the longitudinal axis of the
shaft 10 is the length of the
elastic member 30 between an
end 202 of the
head 20 and the
top surface 401 of the
article 40. As the effective length of the
elastic member 30 changes, tension produced between the
elastic member 30, the
head 20, the
first articles 40 and the
second article 50 is adjusted. In the embodiment, the
elastic member 30 is a coil spring.
Once the
screw 1 is installed, tension created by compression of the
elastic member 30 ensures threads of the
shaft 10 steadily resist against the internal threads of the first and
second articles 40,
50 so that the
screw 1 cannot back out of the through holes of the
articles 40,
50, such as from vibration. When the
elastic member 30 is rotated in the
spiral groove 2011 and the effective length of the
elastic member 30 is changed, enough tension is created to ensure locking the
screw 1 in place and prevent any rotation, thus maintain a tight engagement between the
first article 40 and the
second article 50.
In the embodiment, a
graduation line 60 can be set on the lateral surface of the
shaft 10 so that, for example, when
many screws 1 are employed they can all be adjusted to the same degree of tension, and is configured to indicate the distance D from the
end 202 of the
head 20 to the
top surface 401 of the
first article 40. For example, it means that the distance D is a standard distance when the
graduation line 60 is flush with the
top surface 401. The distance D can be changed by rotating the
elastic member 30 around the longitudinal axis of the
shaft 10 through auxiliary tools, so that the length of the
elastic member 30 from the
end 202 to the
top surface 401 can be changed, and the tension given by the
elastic member 30 can be changed accordingly.
In the embodiment, the
locking screw 1 also includes
flattened portion 70 on lateral sides of the
elastic member 30 to provide gripping surfaces for tools used to adjust the
elastic member 30.
Although the current disclosure has been specifically described on the basis of the exemplary embodiment thereof, the disclosure is not to be construed as being limited thereto. Various changes or modifications may be made to the embodiment without departing from the scope and spirit of the disclosure.